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/*
* Copyright (C) 2014-2016 Firejail Authors
*
* This file is part of firejail project
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "firejail.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <dirent.h>
#include <pwd.h>
#include <grp.h>
//#include <dirent.h>
//#include <stdio.h>
//#include <stdlib.h>
// uid/gid cache
static uid_t c_uid = 0;
static char *c_uid_name = NULL;
static void print_file_or_dir(const char *path, const char *fname, int separator) {
assert(fname);
char *name;
if (separator) {
if (asprintf(&name, "%s/%s", path, fname) == -1)
errExit("asprintf");
}
else {
if (asprintf(&name, "%s%s", path, fname) == -1)
errExit("asprintf");
}
struct stat s;
if (stat(name, &s) == -1) {
if (lstat(name, &s) == -1) {
printf("Error: cannot access %s\n", name);
return;
}
}
// permissions
if (S_ISLNK(s.st_mode))
printf("l");
else if (S_ISDIR(s.st_mode))
printf("d");
else if (S_ISCHR(s.st_mode))
printf("c");
else if (S_ISBLK(s.st_mode))
printf("b");
else if (S_ISSOCK(s.st_mode))
printf("s");
else
printf("-");
printf( (s.st_mode & S_IRUSR) ? "r" : "-");
printf( (s.st_mode & S_IWUSR) ? "w" : "-");
printf( (s.st_mode & S_IXUSR) ? "x" : "-");
printf( (s.st_mode & S_IRGRP) ? "r" : "-");
printf( (s.st_mode & S_IWGRP) ? "w" : "-");
printf( (s.st_mode & S_IXGRP) ? "x" : "-");
printf( (s.st_mode & S_IROTH) ? "r" : "-");
printf( (s.st_mode & S_IWOTH) ? "w" : "-");
printf( (s.st_mode & S_IXOTH) ? "x" : "-");
printf(" ");
// user name
char *username;
int allocated = 0;
if (s.st_uid == 0)
username = "root";
else if (s.st_uid == c_uid) {
assert(c_uid_name);
username = c_uid_name;
}
else {
struct passwd *pw = getpwuid(s.st_uid);
allocated = 1;
if (!pw) {
if (asprintf(&username, "%d", s.st_uid) == -1)
errExit("asprintf");
}
else {
username = strdup(pw->pw_name);
if (!username)
errExit("asprintf");
}
if (c_uid == 0) {
c_uid = s.st_uid;
c_uid_name = strdup(username);
if (!c_uid_name)
errExit("asprintf");
}
}
// print user name, 8 chars maximum
int len = strlen(username);
if (len > 8) {
username[8] = '\0';
len = 8;
}
printf("%s ", username);
int i;
for (i = len; i < 8; i++)
printf(" ");
if (allocated)
free(username);
// group name
char *groupname;
allocated = 0;
if (s.st_uid == 0)
groupname = "root";
else {
struct group *g = getgrgid(s.st_gid);
allocated = 1;
if (!g) {
if (asprintf(&groupname, "%d", s.st_gid) == -1)
errExit("asprintf");
}
else {
groupname = strdup(g->gr_name);
if (!groupname)
errExit("asprintf");
}
}
// print grup name, 8 chars maximum
len = strlen(groupname);
if (len > 8) {
groupname[8] = '\0';
len = 8;
}
printf("%s ", groupname);
for (i = len; i < 8; i++)
printf(" ");
if (allocated)
free(groupname);
char *sz;
if (asprintf(&sz, "%d", (int) s.st_size) == -1)
errExit("asprintf");
printf("%11.10s %s\n", sz, fname);
free(sz);
}
static void print_directory(const char *path) {
assert(path);
struct stat s;
if (stat(path, &s) == -1)
return;
assert(S_ISDIR(s.st_mode));
struct dirent **namelist;
int i;
int n;
n = scandir(path, &namelist, 0, alphasort);
if (n < 0)
errExit("scandir");
else {
for (i = 0; i < n; i++) {
print_file_or_dir(path, namelist[i]->d_name, 0);
free(namelist[i]);
}
}
free(namelist);
}
void sandboxfs_name(int op, const char *name, const char *path) {
EUID_ASSERT();
if (!name || strlen(name) == 0) {
fprintf(stderr, "Error: invalid sandbox name\n");
exit(1);
}
pid_t pid;
if (name2pid(name, &pid)) {
fprintf(stderr, "Error: cannot find sandbox %s\n", name);
exit(1);
}
sandboxfs(op, pid, path);
}
void sandboxfs(int op, pid_t pid, const char *path) {
EUID_ASSERT();
// if the pid is that of a firejail process, use the pid of the first child process
EUID_ROOT();
char *comm = pid_proc_comm(pid);
EUID_USER();
if (comm) {
if (strcmp(comm, "firejail") == 0) {
pid_t child;
if (find_child(pid, &child) == 0) {
pid = child;
}
}
free(comm);
}
// check privileges for non-root users
uid_t uid = getuid();
if (uid != 0) {
uid_t sandbox_uid = pid_get_uid(pid);
if (uid != sandbox_uid) {
fprintf(stderr, "Error: permission denied.\n");
exit(1);
}
}
// full path or file in current directory?
char *fname;
if (*path == '/') {
fname = strdup(path);
if (!fname)
errExit("strdup");
}
else if (*path == '~') {
if (asprintf(&fname, "%s%s", cfg.homedir, path + 1) == -1)
errExit("asprintf");
}
else {
fprintf(stderr, "Error: Cannot access %s\n", path);
exit(1);
}
// sandbox root directory
char *rootdir;
if (asprintf(&rootdir, "/proc/%d/root", pid) == -1)
errExit("asprintf");
if (op == SANDBOX_FS_LS) {
EUID_ROOT();
// chroot
if (chroot(rootdir) < 0)
errExit("chroot");
if (chdir("/") < 0)
errExit("chdir");
// access chek is performed with the real UID
if (access(fname, R_OK) == -1) {
fprintf(stderr, "Error: Cannot access %s\n", fname);
exit(1);
}
// list directory contents
struct stat s;
if (stat(fname, &s) == -1) {
fprintf(stderr, "Error: Cannot access %s\n", fname);
exit(1);
}
if (S_ISDIR(s.st_mode)) {
char *rp = realpath(fname, NULL);
if (!rp) {
fprintf(stderr, "Error: Cannot access %s\n", fname);
exit(1);
}
if (arg_debug)
printf("realpath %s\n", rp);
char *dir;
if (asprintf(&dir, "%s/", rp) == -1)
errExit("asprintf");
print_directory(dir);
free(rp);
free(dir);
}
else {
char *rp = realpath(fname, NULL);
if (!rp) {
fprintf(stderr, "Error: Cannot access %s\n", fname);
exit(1);
}
if (arg_debug)
printf("realpath %s\n", rp);
char *split = strrchr(rp, '/');
if (split) {
*split = '\0';
char *rp2 = split + 1;
if (arg_debug)
printf("path %s, file %s\n", rp, rp2);
print_file_or_dir(rp, rp2, 1);
}
free(rp);
}
}
// get file from sandbox and store it in the current directory
else if (op == SANDBOX_FS_GET) {
// check source file (sandbox)
char *src_fname;
if (asprintf(&src_fname, "%s%s", rootdir, fname) == -1)
errExit("asprintf");
EUID_ROOT();
struct stat s;
if (stat(src_fname, &s) == -1) {
fprintf(stderr, "Error: Cannot access %s\n", fname);
exit(1);
}
// try to open the source file - we need to chroot
pid_t child = fork();
if (child < 0)
errExit("fork");
if (child == 0) {
// chroot
if (chroot(rootdir) < 0)
errExit("chroot");
if (chdir("/") < 0)
errExit("chdir");
// drop privileges
drop_privs(0);
// try to read the file
if (access(fname, R_OK) == -1) {
fprintf(stderr, "Error: Cannot read %s\n", fname);
exit(1);
}
exit(0);
}
// wait for the child to finish
int status = 0;
waitpid(child, &status, 0);
if (WIFEXITED(status) && WEXITSTATUS(status) == 0);
else
exit(1);
EUID_USER();
// check destination file (host)
char *dest_fname = strrchr(fname, '/');
if (!dest_fname || *(++dest_fname) == '\0') {
fprintf(stderr, "Error: invalid file name %s\n", fname);
exit(1);
}
if (access(dest_fname, F_OK) == -1) {
// try to create the file
FILE *fp = fopen(dest_fname, "w");
if (!fp) {
fprintf(stderr, "Error: cannot create %s\n", dest_fname);
exit(1);
}
fclose(fp);
}
else {
if (access(dest_fname, W_OK) == -1) {
fprintf(stderr, "Error: cannot write %s\n", dest_fname);
exit(1);
}
}
// copy file
EUID_ROOT();
copy_file(src_fname, dest_fname);
if (chown(dest_fname, getuid(), getgid()) == -1)
errExit("chown");
if (chmod(dest_fname, 0644) == -1)
errExit("chmod");
EUID_USER();
}
free(fname);
free(rootdir);
exit(0);
}
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